Showerhead assembly and method of servicing assembly for semiconductor manufacturing

ABSTRACT

A method, comprising: providing an adjustable distributor assembly disposed within a showerhead configured to provide selectively adjustable openings through which a cleaning material passes; determining an initial value of a configurable parameter of an adjustable distributor assembly; performing an amount/thickness measurement of a layer including polymeric residues and metal oxide deposits at a cleaning surface of a wafer by a monitoring device; determining whether a variation in the amount/thickness measurement is within an acceptable range; and in response to the variation in the amount/thickness measurement that is not within the acceptable range, automatically adjusting the configurable parameter of the adjustable distributor assembly to set the variation in the amount/thickness measurement within the acceptable range so that the cleaning material that passes through the selectively adjustable openings of the adjustable distributor assembly reduces metal oxide deposits.

CROSS REFERENCE TO RELATED APPLICATION

This Application is a Divisional Application of U.S. Ser. No.17/459,672, filed Aug. 27, 2021, the disclosure of which is incorporatedherein by reference in entirety.

BACKGROUND

In a semiconductor manufacturing process, uniformity of processes is akey factor to improve the production yield and reliability of produceddevices. In particular, in vapor phase processes or plasma processesusing a showerhead to introduce gases into a chamber, maintaining orimproving uniformity of the gases is one of the key factors to improveprocess uniformity.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1 schematically illustrates a pre-clean system and a showerheadused for a semiconductor wafer manufacturing process, according toembodiments of the disclosure.

FIG. 2 illustrates a showerhead according to an embodiment of thedisclosure.

FIGS. 3A, 3B, 3C, 3D, 3E and 3F schematically illustrate adjustabledistributor assemblies including a plurality of control sheets accordingto various embodiments of the disclosure.

FIGS. 4A, 4B and 4C are schematic views of a base sheet and theplurality of control sheets configured to provide selectively adjustableregions, respectively, according to various embodiments of thedisclosure.

FIGS. 5A, 5B and 5C are schematic views of an overlapping amount of abase openings and a control openings with respect to a distributoropening according to various embodiments of the disclosure.

FIGS. 6A, 6B, 6C and 6D are schematic views of adjustable distributorassemblies for improving uniformity of the pre-clean operation accordingto various embodiments of the disclosure.

FIGS. 7A and 7B are schematic views of the adjustable distributorassembly including a plurality of control segments according toembodiments of the disclosure.

FIGS. 8A, 8B, 8C, 8D, 8E and 8F schematically illustrate the adjustabledistributor assembly including the base openings and the controlopenings according to various embodiments of the disclosure.

FIGS. 9A, 9B and 9C schematically illustrate the adjustable distributorassembly including the base sheet according to various embodiments ofthe disclosure.

FIGS. 10A, 10B and 10C schematically illustrate the adjustabledistributor assembly including the plurality of control sheets accordingto various embodiments of the disclosure.

FIG. 11 schematically illustrates a controllable pre-cleaning operationaccording to an embodiment of the disclosure.

FIG. 12 illustrates a flow-chart of a method of using a showerheadassembly, in accordance with an embodiment of the present disclosure.

FIGS. 13A and 13B illustrate a controller in accordance with someembodiments of the disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof the disclosure. Specific embodiments or examples of components andarrangements are described below to simplify the present disclosure.These are, of course, merely examples and are not intended to belimiting. For example, dimensions of elements are not limited to thedisclosed range or values, but may depend upon process conditions and/ordesired properties of the device. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact. Variousfeatures may be arbitrarily drawn in different scales for simplicity andclarity.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The device may be otherwise oriented (rotated 90 degrees orat other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. In addition, the term“made of” may mean either “comprising” or “consisting of.”

The present disclosure relates to an adjustable showerhead assembly thatis designed to improve process (e.g., etching or deposition) uniformityof an etching or a deposition apparatus. In some embodiments, theapparatus is for a pre-clean process of a metal surface, e.g., a Cu orCu alloy surface to remove polymeric residues and reduce metal oxidedeposits, such as copper oxide, before forming a subsequent conductivelayer.

FIG. 1 schematically illustrates a pre-clean system 900 and a showerhead950 used for a semiconductor wafer manufacturing process, according toembodiments of the disclosure. As shown in FIG. 1 , the pre-clean system900 includes a flow inlet 910 that passes pre-cleaning material 920 to aremote plasma source 930. In some embodiments, the pre-cleaning material920 includes at least one of helium gas, H₂O, argon gas, and hydrogengas. In some embodiments, a substrate 999, on which conductive patterns(e.g., Cu wiring patterns) are formed, is placed on a pedestal 970 andthe activated pre-cleaning material 920 (radicals) activated by theremote plasma source 930 enters into the chamber 960 through ashowerhead 950.

In some embodiments, the activated remote plasma source 930 of thepre-clean system 900 provides hydrogen ion/radicals. The pre-cleansystem 900 further includes an applicator tube 935 and an ion filter940. The applicator tube 935 of the pre-clean system 900 is connectedbetween the remote plasma source 930 and the cleaning chamber 960. Theion filter 940 of the pre-clean system 900 is disposed on the applicatortube 935 and located between the remote plasma source 930 and thecleaning chamber 960, and is used to filter ions in the applicator tube935.

In some embodiments, the plasma is generated and exists within theremote plasma source 930, and the generated plasma does not enter intothe cleaning chamber 960, but reactive hydrogen radicals H* aregenerated by the remote plasma source 930 and enter into the cleaningchamber 960 through the applicator tube 935, which passes through analuminum lid 945. Only radicals (i.e., hydrogen radicals H*) enter thecleaning chamber 960, not the plasma, in some embodiments.

In some embodiments, the cleaning chamber 960 of the pre-clean system900 includes a pedestal (or a stage or a substrate holder) 970, aheating element (e.g., heater) 965, and a showerhead 950. The pedestal970 of the pre-clean system 900 is located within the cleaning chamber960, and is used to support a wafer or substrate 999. The heatingelement 965 of the pre-clean system 900 is located within the pedestal970, and is used to heat the pedestal 970 to a predeterminedtemperature. The pedestal 970 heated by the heating element 965 of thecleaning chamber 960 helps increase the process efficiency, e.g.,increase the etching rate. The showerhead 950 of the pre-clean system900 is located within the cleaning chamber 960 and is disposed over thewafer or substrate 999. The hydrogen ions/radicals are generated by theremote plasma source 930 and pass through the showerhead 950 and proceedonto the cleaning surface of the wafer or substrate 999. The hydrogenradicals H* that pass through the showerhead 950 remove polymericresidues on the wafer or substrate 999 and reduce metal oxide deposits,such as copper oxide, deposited on the Cu wiring patterns formed on thewafer or substrate 999 in some embodiments.

In some embodiments, the cleaning chamber 960 of the pre-clean system900 further includes a turbo pump, a pendulum valve, a radio frequency(RF) resonator, RF cables and a bell jar.

FIG. 2 is an isometric view of the showerhead 950 that includes theshowerhead distributor 954 where an inert gas flow is ejected throughthe showerhead distributor 954 in various embodiments. In someembodiments, a substrate 999 (shown in FIG. 1 ) is placed on thepedestal 970 (shown in FIG. 1 ), then the pre-cleaning material 920,such as a hydrogen gas, flows through the flow inlet 910 and passesthrough the showerhead 950. The radicals of pre-cleaning material 920subsequently impinge on the substrate 999 through openings in the faceof the showerhead distributor 954 opposing the substrate 999.

As shown in FIG. 2 , the showerhead 950 includes a gasket material 952,the showerhead distributor 954, and the showerhead housing 956, in someembodiments. The showerhead distributor 954 is a circular plate having aplurality of through holes, and located within the showerhead housing956 of the showerhead 950. In some embodiments, a gasket material 952seals the showerhead housing 956 and prevents the pre-cleaning material920 from evacuating from the showerhead 950. The gasket material 952,according to embodiments of the disclosure, is made of PE (polyethylene)or PTFE (polytetrafluoroethylene). In some embodiments, the gasketmaterial 952 is made of an elastic material. Examples of the elasticmaterial forming the gasket material 952 include crosslinked rubbermaterials such as silicone rubber, chloroprene rubber, EPDM, NBR,natural rubber, and fluororubber. In some embodiments, some examples ofthe silicone rubber include (meth) acryloyloxy group-containingpolysiloxane, vinyl polysiloxane, mercaptoalkyl group-containingpolysiloxane, and the like.

The showerhead is one of the key parts for the uniform pre-cleaningprocess. The process uniformity of the pre-cleaning depends on theopenings' size in the showerhead distributor. However, it is typicalthat the showerhead distributor includes a plurality of openings(through holes) that have only one fixed opening size. When thicknessuniformity of the processed substrate during the pre-clean operation outof a specified tolerance range, the only way to conventionally solve theproblem is to replace the showerhead with another showerhead. As such,there is a need for new configuration of a showerhead, which eliminatesthe need to replace the showerhead.

Embodiments of the present disclosure are directed to atunable/controllable showerhead assembly that is designed forselectively adjusting gas flow amounts toward the shower head so thatprocess uniformity is maintained or improved during a pre-cleanoperation.

As shown in FIGS. 3A, 3B and 3C, in some embodiments according to thisdisclosure, the showerhead assembly includes an adjustable distributorassembly 1100 disposed above the shower head distributor 954, a gasketmaterial 952, and the showerhead housing 956. FIG. 3A is a plan view ofadjustable distributor assembly 1100 in the X-Y plane, and FIG. 3B is across sectional view of adjustable distributor assembly 1100 in the X-Zplane. FIG. 3C is an isometric view of the showerhead assembly.

The adjustable distributor assembly 1100, as shown in FIGS. 3A-3C,includes a base sheet 1130 and a plurality of control sheets 1160. Insome embodiments, as shown in FIG. 3A, the base sheet 1130 includes aplurality of base sheets 1130 a, 1130 b. Each of the plurality of basesheets includes base openings 1132 and has a fan shape having aninterior angle in a range from about 10 degrees to about 180 degrees insome embodiments. In other embodiments, as shown in FIG. 3C, the basesheet 1130 is a circular plate having base openings 1132. The base sheet1130 includes base openings 1132 (shown in FIG. 3C). In someembodiments, each of the plurality of control sheets 1160 also includescontrol openings 1162 and has a fan shape having an interior angle in arange from about 10 degrees to about 180 degrees. In some embodiments,the adjustable distributor assembly 1100 further includes a sheetadapter 1150 that is configured to attach the plurality of controlsheets 1160 to the base sheet 1130. Each of the plurality of controlsheets 1160 is rotatably coupled to the sheet adapter 1150 about a pivotpoint of the fan shape. The adjustable distributor assembly 1100 isdisposed within the showerhead housing 956 (shown in FIG. 2 ) of theshowerhead. In some embodiments, the base sheet 1130 is not used and thecontrol sheet 1160 is disposed directly on or above the showerheaddistributor 954 (shown in FIG. 2 ). In some embodiments, the base sheet1130 is in contact with the showerhead distributor 954 and in otherembodiments, there is a space (e.g., about 1 mm to about 20 mm) betweenthe base sheet 1130 and the showerhead distributor 954. In someembodiments, the base sheet 1130 is in contact with the control sheet1160 and in other embodiments, there is a space (e.g., about 0.1 mm toabout 5 mm) between the base sheet 1130 and the control sheet 1160.

For example, as shown in FIG. 3D, the control openings 1162 of theplurality of control sheets 1160 and the base openings 1132 of the basesheet 1130 have the same diameter. In some embodiments, as shown in FIG.3E, the adjustable distributor assembly 1100 may rotate and/or moveplurality of control sheets 1160, so that the control openings 1162 ofthe plurality of control sheets 1160 slidably cover the base openings1132 of the base sheet 1130 to provide selectively adjustable openings1199, as shown in FIG. 3F. Here, “selectively adjustable” meansoverlapping opening size and/or regions that are adjustable within theshowerhead by slidably mating a base opening and a control openingselected by a user, thereby adjusting an amount of gas passing throughthe adjustable distributor assembly.

FIGS. 4A, 4B and 4C are schematic views of the base sheet and theplurality of control sheets configured to provide selectively adjustableregions, respectively, according to various embodiments of thedisclosure. As shown in FIGS. 4A and 4B, in some embodiments, theplurality of control sheets 1160 is configured to slidably mate with thebase sheet 1130 to provide selectively adjustable openings 1199 (shownin FIG. 4B). In some embodiments, the sheet adapter 1150 (shown in FIG.4B) connects the plurality of control sheets 1160 and the base sheet1130 together.

As shown in FIG. 4A, in some embodiments, the control openings 1162 ofthe plurality of control sheets 1160 and the base openings 1132 of thebase sheet 1130 (and a distributor opening 955 of the showerheaddistributor 954 in some embodiments) have the same diameter (or openingarea). In some embodiments, the adjustable distributor assembly 1100includes the plurality of control sheets 1160 that overlaps the basesheet 1130 above the top of the showerhead distributor 954, such that anoverlapping amount of the control openings 1162 of the plurality ofcontrol sheets 1160 and the base openings 1132 of the base sheet 1130(and the distributor opening 955 of the showerhead distributor 954) is100%. In such embodiments, there is no intersecting area among theopenings 1162, 1132, 954.

As shown in FIG. 4B, by adjusting the position of the plurality ofcontrol sheets 1160 relative to the base sheet 1130, the overlappingamount of the base openings 1132 and the control openings 1162 can beadjusted from 0% to 100%, thereby adjusting an amount of gas passingthrough the adjustable distributor assembly 1100. For example, while thebase opening 1132 is fully covered and closed by one or more of theplurality of control sheets 1160, the base opening 1132 can be partiallycovered by one or more of the plurality of control sheets 1160, therebylocally controlling gas flow amounts passing through the adjustabledistributor assembly 1100. In some embodiments, each of the plurality ofcontrol sheets 1160 makes a rotational movement (around the sheetadapter 1150), and in other embodiments, each of the plurality ofcontrol sheets 1160 slidably moves in one or more linear directions. Asshown in FIGS. 4A-4C, only the plurality of control sheets 1160 and thebase sheet 1130 provide locally different gas flow amounts towards theshower head distributor 954 in some embodiments. As such, in thisconfiguration, a size of the distributor opening 955 of the showerheaddistributor 954 does not affect a performance of the adjustabledistributor assembly 1100.

FIG. 4C is a schematic view of the base sheet 1130 and the plurality ofcontrol sheets 1160 configured to provide selectively adjustable regions1900 according to an embodiment of the disclosure. As shown in FIG. 4C,the selectively adjustable regions 1900 includes overlapping regions1902 a, 1902 b that are adjustable within the showerhead by slidablymating the base openings 1132 and the control openings 1162 through anangle from 0 degree to 360 degrees, thereby adjusting an amount of gaspassing through the adjustable distributor assembly 1100. In someembodiments, the sheet adapter 1150 connects the plurality of controlsheets 1160 and the base sheet 1130 together. In some embodiments, eachof the plurality of control sheets 1160 makes a rotational movement(around the sheet adapter 1150 shown in FIG. 3C), and in otherembodiments, each of the plurality of control sheets 1160 slidably movesin one or more linear directions. In some embodiments, an angularspacing between the base openings 1132 and the control openings 1162 inthe angular direction and the angular spacing in the radial directionare taken into consideration.

FIGS. 5A, 5B and 5C are schematic views of an overlapping amount of baseopenings in the base sheet 1130 and control openings in the controlsheet 1160 according to various embodiments of the disclosure. As shownin FIGS. 5A, 5B and 5C, in some embodiments, the control openings 1162of the plurality of control sheets 1160 and the base openings 1132 ofthe base sheet 1130 include the same diameter (or opening area), and adifferent diameter (or opening area) of the distributor opening 955 ofthe showerhead distributor 954. In such embodiments, the adjustabledistributor assembly 1100 includes the plurality of control sheets 1160that slidably mate with the base sheet 1130 on top of the showerheaddistributor 954, such that an overlapping amount of the control openings1162 of the plurality of control sheets 1160, the base openings 1132 ofthe base sheet 1130, and the distributor opening 955 of the showerheaddistributor 954 is adjusted from 0% to 100%.

As shown in FIG. 5B, by adjusting the position of the plurality ofcontrol sheets 1160 relative to the base sheet 1130, the overlappingamount of the base openings 1132 and the control openings 1162 areadjusted from 0% to 100%, thereby adjusting an amount of gas passingthrough the adjustable distributor assembly 1100. For example, as shownin FIG. 5C, while the distributor opening 955 c is fully open by theplurality of control sheets 1160 and the base sheet 1130, thedistributor opening 955 d is partially covered and the distributoropening 955 e is fully closed, thereby the adjustable distributorassembly 1100 provides the selectively adjustable openings 1199 by anoverlapping relationship between the plurality of control sheets and thebase sheet. As shown in FIGS. 5A-5C, the plurality of control sheets1160, the base sheet 1130 and the showerhead distributor 954 providelocally different gas amount flow towards the cleaning surface 998 ofthe substrate 999 (shown in FIG. 11 ). As such, in this configuration, asize of the distributor opening 955 of the showerhead distributor 954affects the performance of the adjustable distributor assembly 1100.

FIGS. 6A, 6B, 6C and 6D are schematic views of adjustable distributorassemblies for improving the uniformity of the pre-clean operationaccording to various embodiments of the disclosure. In some embodiments,as shown in the cross section of FIG. 6A, an etching rate of the rightside of the wafer increases, causing a thinner remaining film 996. Insuch a case, as shown in FIG. 6B, some of the base openings 1132 locatedat the right side are partially or fully closed by the control sheets toreduce the etching gas flow (radical flow), thereby adjusting (reducing)the etching rate at the right side. For example, the adjustabledistributor assembly 1100 rotates and/or moves a control sheet 1160 b,so that the control openings 1162 of the plurality of control sheets1160 slidably cover the base openings 1132 of the base sheet 1130 toprovide selectively adjustable openings 1198. As a result, theadjustable distributor assembly 1100 provides a smaller amount of thepre-cleaning material directed towards the thinner remaining film 996 ofthe cleaning surface of the substrate, thereby improving the thicknessuniformity of the remaining film on the substrate during the pre-cleanoperation. Accordingly, it is possible to balance the etching ratesbetween the left regions and the right regions and thus obtain a uniformremaining film thickness, thereby improving the uniformity of thepre-clean operation.

In some embodiments, after pre-clean process, the etching amount(remaining thickness) is measured and when there is non-uniformity stillremaining, the hole-overlapping amount is adjusted to increase ordecrease the gas amount. In some embodiments, an in-situ monitoring ofthe etching amount and dynamic adjusting the overlapping amount of thebase openings 1132 and the control openings 1162 is performed. Invarious embodiments, the shapes/locations of the plurality of controlsheets 1160 with respect to the base sheet 1130 are adjusted tocompensate for the thickness non-uniformity.

As shown in FIGS. 6C and 6D, in some embodiments, the adjustabledistributor assembly 1100 further includes a covering sheet 1164. Thecovering sheet 1164 is configured to slidably mate with the base sheet1130 and/or the plurality of control sheets 1160, such that thedistributor opening 955 can be fully closed by the covering sheet 1164when the combination of the control openings 1162 of the plurality ofcontrol sheets 1160 and the base openings 1132 of the base sheet 1130cannot provide the selectively adjustable openings 1198. In someembodiments, as shown in FIG. 6C, a diameter of the covering sheet 1164and the base sheet 1130 and/or the plurality of control sheets 1160 aredifferent. In other embodiments, as shown in FIG. 6D, a diameter of thecovering sheet 1164 and the base sheet 1130 and/or the plurality ofcontrol sheets 1160 are about the same. In some embodiments, an internalfan angle 1167 of the covering sheet 1164 ranges from 0 degree to 360degrees.

FIGS. 7A and 7B are schematic views of the adjustable distributorassembly including a plurality of control segments according toembodiments of the disclosure. In some embodiments, as shown in FIGS. 7Aand 7B, the adjustable distributor assembly 1100 further includes aplurality of control segments 1160 a, 1160 b, and 1160 c. In someembodiments, as shown in FIG. 7A, the plurality of control segments 1160a, 1160 b, 1160 c are positioned between the base openings 1132 of thebase sheet 1130 during a normal situation, so that no base openings 1132are covered by the plurality of control sheets (0% overlap). There is nobase sheet 1130 used in FIGS. 7A-7B. As shown in FIG. 7B, when there isa need, the distributor opening 955 f can be fully covered by theplurality of control segments, such as 1160 c including a smallerdiameter than that of the distributor opening 955 f, thereby theadjustable distributor assembly provides the selectively adjustableopenings by an overlapping relationship between the plurality of controlsheets and the distributor opening 955 of the showerhead distributor954. As shown in FIGS. 7A-7C, only the plurality of control segments1160 a, 1160 b, 1160 c provide locally different gas flow amountstowards the shower head distributor 954. As such, in this configuration,a size of base openings 1132 of the base sheet 1130 and the distributoropening 955 of the showerhead distributor 954 do not affect aperformance of the adjustable distributor assembly 1100.

In some embodiments, as shown in FIG. 7A, each of the plurality ofcontrol segments 1160 a, 1160 b, 1160 c includes the control openings1162 a, 1162 b, 1162 c that have a different diameter from each other.For example, a diameter of the control openings 1162 a is about 0.3-0.7mm, a diameter of the control openings 1162 b is about 0.8-1.2 mm, and adiameter of the control openings 1162 c is about 4-6 mm. In otherembodiments, each of the plurality of control segments 1160 d includesno control openings.

As shown in FIG. 7B, in some embodiments, two or more of the pluralityof control segments 1160 a 1160 b and 1160 c generate the selectivelyadjustable regions 1900 by partially closing the distributor opening 955of the showerhead distributor 954 at the locations corresponding to,e.g., thinner remaining film region of the cleaning surface (shown inFIG. 6A). In some embodiments, the plurality of control sheets 1160 dand 1160 e generate the selectively adjustable regions 1900 by fullyclosing some of the base openings.

In some embodiments, the adjustable distributor assembly 1100 furtherincludes a driving mechanism 1400 (shown in FIG. 11 ) to move thecontrol sheets 1160. In some embodiments, the driving mechanism includesone or more motors, actuators (e.g., piezo actuators), gears, pistons,or any other suitable mechanism to slide and/or rotate the controlsheets 1160. In some embodiments, the driving mechanism includes acontroller coupled to a monitoring system (e.g., cameras, thicknessmeasurement tools, etc.) to monitor an etching amount, and to controlthe positions of the control sheets 1160.

In some embodiments, the base sheet 1130 and the plurality of controlsheets 1160 further include a mechanism to fan out when needed, andsubstantially concealed within the showerhead housing 956 (shown in FIG.2 ) of the showerhead when not in use.

FIGS. 8A, 8B, 8C and 8D schematically illustrate the adjustabledistributor assembly 1100 including the base sheet 1130 having the baseopenings 1132 and the control sheet 1160 having the control openings1162 according to an embodiment of the disclosure. The base openings1132 are disposed within the base sheet 1130, and the control openings1162 are disposed within the plurality of control sheets 1160 throughwhich the gas flows, as shown in FIGS. 8A-8D. As shown in FIG. 8A, insome embodiments, the base openings 1132 and/or the control openings1162 are arranged in a concentric arrangement. In some embodiments, thecontrol sheet 1160 has a full circular shape and in other embodiments,the control sheet 1160 has a fan shape, while the base sheet 1130 has afull circular shape (a circular plate or an annular shape as shown inFIG. 8D).

In some embodiments, each of the base openings 1132 and/or the controlopenings 1162 has a diameter d1 ranging from about 0.01 mm to about 1mm. In some embodiments, each of the base openings 1132 and/or thecontrol openings 1162 has a diameter d1 ranging from about 0.05 mm toabout 0.5 mm. In some embodiments, the diameter d1 of the base openings1132 and/or the control openings 1162 is about 0.1 mm to 0.3 mm. In someembodiments, the base openings 1132 and/or the control openings 1162have an angular spacing w1, w2 along the angular direction and theradial direction ranging from about 0.5 mm to about 24 mm. In someembodiments, the base openings 1132 and/or the control openings 1162have an angular spacing ranging from about 3 mm to about 10 mm. In someembodiments, the base openings 1132 and/or the control openings 1162have an angular spacing of about 5-7 mm. In some embodiments, an angularspacing in the angular direction and the angular spacing in the radialdirection are about the same. In other embodiments, an angular spacingin the angular direction and the radial direction are different.

As shown in FIG. 8E, if the diameter of the base openings 1132 and/orthe control openings 1162 is too large, the adjustable distributorassembly cannot provide selectively adjustable openings effectively. Forexample, while the overlapping amount 1198 a adjusts an area of thedistributor opening 955 a, the overlapping amount 1198 b does not adjustan area of the distributor opening 955 b of the showerhead distributor.As shown in FIG. 8F, if the diameter of the base openings 1132 and/orthe control openings 1162 is too small, the overlapping amount 1198 cmay adjust an area of the distributor opening 955 c, but an overlappingamount of the base openings 1132 and the control openings 1162 cannot beadjusted all the way down to 0% of the distributor opening 955 c of theshowerhead distributor. In addition, the gas flow may become undesirablyhigh.

In some embodiments, the adjustable distributor assembly 1100 includesvarious patterns of the base openings 1132 and/or the control openings1162. In some embodiment, the base openings and/or the control openingsare arranged in concentric circles surrounding a central opening, asshown in FIG. 8A. The patterns of the base openings 1132 and/or thecontrol openings 1162 are not limited to the embodiments shown herein.As shown in FIGS. 8B-8C, in some embodiments, the base openings and/orthe control openings are arranged in lines, where the base openingsand/or the control openings in alternating lines are staggered relativeto immediately adjacent lines. In other embodiments, other patterns,such as a spiral pattern, random pattern, etc. are within the scope ofthis disclosure.

FIGS. 9A, 9B and 9C schematically illustrate the adjustable distributorassembly 1100 including the base sheet according to an embodiment of thedisclosure. As shown in FIG. 9A, the base sheet 1130 has a symmetrichole distribution (concentric) to provide uniform etching. However, whenthe perfect uniformity cannot be obtained, local variations can becompensated by adjusting the opening/hole size by using control sheet byadjusting overlapping or closure amount. As shown in FIG. 9B, in someembodiments, the base sheet 1130 includes first openings 1145 and/orsecond openings 1147 that are configured to eject the cleaning material.In some embodiments, the first openings 1145 and the second openings1147 have a different opening area. In such an embodiment, the firstopenings 1145 and the second openings 1147 have a different diameter. Asshown in FIG. 9C, a shape of the first openings 1145 and the secondopenings 1147 are not particularly limited. For example, in anembodiment, the shape of the first openings 1145 and the second openings1147 is a circle, an ellipse, a triangle, and a regular or irregularconvex polygon. In some embodiments, the first openings 1145 and thesecond openings 1147 have a different shape. In some embodiments, thefirst openings 1145 and the second openings 1147 have the same shape, asshown in FIGS. 9A and 9B. In some embodiments, no first opening isprovided (closed) in the base sheet 1130, and in other embodiments, nosecond opening is provided (closed) in the base sheet 1130.

FIGS. 10A, 10B and 10C schematically illustrate the adjustabledistributor assembly including the plurality of control sheets accordingto an embodiment of the disclosure. The plurality of control sheets 1160includes third openings 1175 and/or fourth openings 1177 that areconfigured to eject the cleaning material. As shown in FIG. 10A, in someembodiments, the third openings 1175 and the fourth openings 1177 have adifferent diameter. As shown in FIG. 10B, in some embodiments, the thirdopenings 1175 and the fourth openings 1177 have the same diameter. Theshape of the third openings 1175 and/or the fourth openings 1177 are notparticularly limited. For example, in an embodiment, the shape of thethird openings 1175 and/or the fourth openings 1177 is a circle, anellipse, a triangle, and a regular or irregular convex polygon. In someembodiments, the third openings 1175 and the fourth openings 1177 have adifferent shape, as shown in FIG. 10C. In some embodiments, the thirdopenings 1175 and the fourth openings 1177 have the same shape, as shownin FIGS. 10A and 10B.

In some embodiments, the plurality of control sheets 1160 is fixedlyattached or integrated with the base sheet 1130. In alternativeembodiments, the plurality of control sheets 1160 is detachable from thebase sheet 1130.

The adjustable distributor assembly 1100, according to embodiments ofthe disclosure, is made of at least one of quartz, polyethylene (PE) andpolytetrafluoroethylene (PTFE).

FIG. 11 schematically illustrates a controllable pre-cleaning operationaccording to an embodiment of the disclosure. In some embodiments, thecontrollable pre-cleaning operation is triggered based on monitored andsensed polymeric residues and/or metal oxide deposits, such as copperoxide.

As shown in FIG. 11 , in some embodiments, a controller 70 is configuredto monitor an amount/thickness of a layer including polymeric residuesand/or metal oxide deposits, such as copper oxide, at the cleaningsurface 998 of the substrate 999. In some embodiments, the base sheet1130 and the plurality of control sheets 1160 is coupled to a moving andsupporting mechanism and is connected to supporting devices such as amotor 1470. By using a monitoring device 1420, the controller 70 adjustsconfigurable parameters when the amount/thickness of the layer removedduring the pre-clean operation of the cleaning surface 998 is more thana threshold amount or greater than a threshold thickness/size, andregulates the configurable parameters of the adjustable distributorassembly 1100, an overlapping amount of the base openings 1132 and thecontrol openings 1162 that can be locally adjusted from 0% to 100%, andan angular overlapping amount of the base openings 1132 and the controlopenings 1162 that can be extended from 0 degree to 360 degrees byoperating the motor 1470. In such embodiments, the controllablepre-clean operation includes configurable parameters that include one ormore of an area of openings, a type/shape of openings, a region ofopenings, a type of gas/fluids, a flow rate or pressure, a gas/liquidtemperature, and/or a showerhead height with respect to the cleaningsurface 998 of the substrate 999, etc. The configurable parameters ofthe controllable pre-clean operation, according to some embodiments,further include control parameters to control the supporting devices,such as a motor 1470, a turbo pump and a pendulum valve. In someembodiments, the monitoring device 1420 is a camera. In someembodiments, the monitoring device 1420 includes an image processunit/algorithm using the camera. In some embodiments, the ejection ofthe pre-cleaning material from the adjustable distributor assembly 1100is stopped when the monitoring device detects the amount of thepolymeric residues and/or metal oxide deposits, such as copper oxide, onthe cleaning surface 998 of the substrate 999 is below the thresholdamount. Any appropriate controlling configuration regarding automaticand/or manual operation is contemplated and is not limited in thisregard.

As shown in FIG. 11 , in response to a measurement of a lower thickness996 of a film, some of the base openings and control openings located atthe measured portion are partially or fully closed by the control sheetsto reduce the etching gas flow (radical flow), thereby adjusting(reducing) the etching rate at the measured portion. For example, theadjustable distributor assembly 1100 rotates and/or moves a controlsheet, so that the control openings 1162 of the plurality of controlsheets 1160 slidably cover the base openings 1132 of the base sheet 1130to provide selectively adjustable openings. As a result, the adjustabledistributor assembly 1100 provides the smaller amount of thepre-cleaning material directed towards the thinner remaining film 996 ofthe cleaning surface of the substrate, thereby improving the thicknessuniformity of the remaining film on the substrate during the pre-cleanoperation.

In some embodiments, the polymeric residues are analyzed by scanningelectron microscopy (SEM). In other embodiments, the polymeric residuesare analyzed by energy dispersive X-ray spectroscopy (EDX), totalreflection X-ray fluorescence (TXRF) and/or any suitable method ofelemental analysis. In some embodiments, the method further includesidentifying a source of the polymeric residues and/or metal oxidedeposits, such as copper oxide, based on the analysis. In otherembodiments, the method further includes counting a number of polymericresidues before the pre-clean operation. In some alternativeembodiments, the method further includes counting a number of polymericresidues after the pre-clean operation.

FIG. 12 illustrates a flow-chart of a method 1000 of using theshowerhead assembly with the feedback control operation, in accordancewith an embodiment of the present disclosure.

In some embodiments, a showerhead is disposed over a wafer within acleaning chamber, in which the showerhead configured to eject cleaningmaterial through the showerhead toward a cleaning surface of the wafer.The adjustable distributor assembly is placed within a showerhead and isconfigured to provide selectively adjustable openings through which thecleaning material passes. In some embodiments, the adjustabledistributor assembly includes a base sheet including base openings and aplurality of control sheets including control openings and configured toslidably mate with the base sheet to provide selectively adjustableopenings.

The method includes, at S1010, determining an initial value of aconfigurable parameter of an adjustable distributor assembly. In someembodiments, the configurable parameter includes an overlapping amountof the base openings and the control openings that can be adjusted from0% to 100%, and an angular overlapping amount of the base openings andthe control openings that can be extended from 0 degree to 360 degrees.

At S1020, a measurement of amount/thickness of the layer removed duringthe pre-clean operation of the cleaning surface is performed by amonitoring device to determine if the amount/thickness of the layerremoved during the pre-clean operation of the cleaning surface 998 ismore than a threshold amount or greater than a threshold thickness/size.

At S1030, it is determined whether a variation in the amount/thicknessmeasurement of the layer removed during the pre-clean operation iswithin an acceptable range. In some embodiments, the monitoring deviceincludes a logic circuit programmed to generate a predetermined signalwhen the detected variation in amount/thickness measurement is notwithin an acceptable range. For example, a signal is generated when thedetected variation in amount/thickness measurement is less than acertain threshold value.

Then, at S1040, an overlapping amount of the base openings and thecontrol openings is automatically adjusted according to the monitoringresults. In some embodiments, the adjustable distributor assemblyrotates and/or moves a plurality of control sheets, so that the controlopenings of the plurality of control sheets slidably cover the baseopenings of the base sheet to provide the overlapping amount between 0%and 100% to one or more areas where the remaining thickness is more thanthe threshold. In other embodiments, the adjustable distributor assemblyrotates and/or moves a plurality of control sheets, such that an angularoverlapping amount of the base openings and the control openings isextended between 0 degree and 360 degrees. As a result, the adjustabledistributor assembly 1100 provides a smaller amount of the pre-cleaningmaterial directed towards a selected/localized area/regions of thecleaning surface of the substrate, thereby improving the thicknessuniformity of the remaining film on the substrate during the pre-cleanoperation. In other embodiments, by adjusting the positions of thecontrol sheets, the amount of the pre-cleaning material is locallyincreased.

FIGS. 13A and 13B illustrate a configuration of the controller 70 inaccordance with some embodiments of the disclosure. In some embodiments,a computer system 2000 is used as the controller 70. In someembodiments, the computer system 2000 performs the functions of thecontroller as set forth above.

FIG. 13A is a schematic view of a computer system. All of or a part ofthe processes, method and/or operations of the foregoing embodiments canbe realized using computer hardware and computer programs executedthereon. In FIG. 13A, a computer system 2000 is provided with a computer2001 including an optical disk read only memory (e.g., CD-ROM orDVD-ROM) drive 2005 and a magnetic disk drive 2006, a keyboard 2002, amouse 2003, and a monitor 2004.

FIG. 13B is a diagram showing an internal configuration of the computersystem 2000. In FIG. 13B, the computer 2001 is provided with, inaddition to the optical disk drive 2005 and the magnetic disk drive2006, one or more processors, such as a micro processing unit (MPU)2011, a ROM 2012 in which a program such as a boot up program is stored,a random access memory (RAM) 2013 that is connected to the MPU 2011 andin which a command of an application program is temporarily stored and atemporary storage area is provided, a hard disk 2014 in which anapplication program, a system program, and data are stored, and a bus2015 that connects the MPU 2011, the ROM 2012, and the like. Note thatthe computer 2001 may include a network card (not shown) for providing aconnection to a LAN.

The program for causing the computer system 2000 to execute thefunctions of an apparatus for controlling the apparatus in the foregoingembodiments may be stored in an optical disk 2021 or a magnetic disk2022, which are inserted into the optical disk drive 2005 or themagnetic disk drive 2006, and transmitted to the hard disk 2014.Alternatively, the program may be transmitted via a network (not shown)to the computer 2001 and stored in the hard disk 2014. At the time ofexecution, the program is loaded into the RAM 2013. The program may beloaded from the optical disk 2021 or the magnetic disk 2022, or directlyfrom a network. The program does not necessarily have to include, forexample, an operating system (OS) or a third party program to cause thecomputer 2001 to execute the functions of the controller 70 in theforegoing embodiments. The program may only include a command portion tocall an appropriate function (module) in a controlled mode and obtaindesired results.

Embodiments of the present disclosure minimize polymeric residues andmetal oxide deposits, such as copper oxide, and provide improvedthickness uniformity of the substrate during the pre-clean operation.Higher yield of semiconductor devices and higher quality semiconductordevices are obtained from methods according to the present disclosure.Embodiments of the present disclosure enable the use of a standalonetrack processing configuration and enables the processing of wafers athigher wafer throughput and improves processing configurationflexibility. Embodiments of the present disclosure further provide thebenefit of reducing downtime during maintenance and servicingphotolithographic tools and masks. The design of the pre-clean systemand showerhead assembly allows for faster maintenance with reducedservicing time. The adaptation of the pre-clean system allows animproved process resulting in reduced manpower required to perform themaintenance, and an increased output of conforming servicing items ofthe photolithographic tools—both of which ultimately result in acost-savings. As such, the photolithographic tools and masks are moreefficiently used. However, it will be understood that not all advantageshave been necessarily discussed herein, no particular advantage isrequired for all embodiments or examples, and other embodiments orexamples may offer different advantages.

An embodiment of the disclosure is a device for cleaning a wafer in asemiconductor manufacturing apparatus that includes a showerhead and anadjustable distributor assembly. The showerhead is disposed over a waferstage within a cleaning chamber and configured to eject cleaningmaterial through the showerhead towards a cleaning surface of a wafer.The adjustable distributor assembly is disposed within the showerheadthrough which the cleaning material passes. The adjustable distributorassembly includes a base sheet and a plurality of control sheets. Thebase sheet includes base openings, and the plurality of control sheetsinclude control openings and are configured to slidably mate with thebase sheet to provide selectively adjustable openings.

In some embodiments, the selectively adjustable openings includes anadjustable opening size. In some embodiments, the adjustable distributorassembly further includes a plurality of control segments positionedbetween the base openings of the base sheet. In some embodiments, theadjustable distributor assembly further includes a sheet adapterconfigured to slidably attach the plurality of control sheets to thebase sheet. In some embodiments, each of the plurality of control sheetsis rotatably coupled to the sheet adapter at a pivot point of theplurality of control sheets. In some embodiments, hydrogen radicals passthrough the showerhead to reduce metal oxide deposits on the wafer. Insome embodiments, the control openings of the plurality of controlsheets include first openings and second openings that have differentopening areas. In some embodiments, the base openings and the controlopenings are arranged in a concentric arrangement. In some embodiments,a shape of the base and control openings includes at least one of acircle, an ellipse, a triangle, and a regular or irregular convexpolygon. In some embodiments, the adjustable distributor assemblyfurther includes a covering sheet without openings.

An embodiment of the disclosure is an apparatus for cleaning a waferthat includes a showerhead and an adjustable distributor assembly. Theshowerhead is disposed over a wafer stage within a cleaning chamber andconfigured to eject cleaning material through the showerhead towards acleaning surface of a wafer. The adjustable distributor assemblydisposed within the showerhead and configured to provide selectivelyadjustable openings through which the cleaning material passes. Theadjustable distributor assembly includes a base sheet and a plurality ofcontrol sheets. The base sheet includes base openings, the plurality ofcontrol sheets and a feedback controller. The plurality of controlsheets include control openings and are configured to slidably mate withthe base sheet to provide selectively adjustable openings. The feedbackcontroller is configured to adjust the selectively adjustable openingsof the adjustable distributor assembly.

In some embodiments, the adjustable distributor assembly is made of atleast one of quartz, polyethylene (PE) and polytetrafluoroethylene(PTFE). In some embodiments, the apparatus further includes a pluralityof control segments positioned between the base openings of the basesheet. In some embodiments, the base sheet is a circular plate.

According to another aspect of the present disclosure, a method ofcontrolling a feedback control operation of a showerhead disposed over awafer within a cleaning chamber. In such embodiments, an adjustabledistributor assembly is disposed within the showerhead configured toprovide selectively adjustable openings through which a cleaningmaterial passes is provided. The adjustable distributor assemblyincludes a base sheet and a plurality of control sheets. The base sheetincludes base openings. The plurality of control sheets includes controlopenings and are configured to slidably mate with the base sheet toprovide selectively adjustable openings. The method includes determiningan initial value of a configurable parameter of an adjustabledistributor assembly. Then, an amount/thickness measurement of a layerincluding polymeric residues and metal oxide deposits at a cleaningsurface of the wafer is performed by a monitoring device. Subsequently,it is determined whether a variation in an amount/thickness measurementis within an acceptable range. In response to a variation in theamount/thickness measurement that is not within the acceptable range ofvariation in the amount/thickness measurement, the configurableparameter of the adjustable distributor assembly is automaticallyadjusted to set the variation in amount/thickness measurement within theacceptable range so that the cleaning material that passes through theselectively adjustable openings of the adjustable distributor assemblyreduces metal oxide deposits.

In some embodiments, the configurable parameter includes one or more ofan area of openings, a shape of openings, a region of openings, a typeof gas, a flow rate or pressure, a gas/liquid temperature, and/or ashowerhead height with respect to the cleaning surface of the wafer. Insome embodiments, plasma is generated within a remote plasma source thatdoes not enter into a cleaning chamber. In some embodiments, hydrogenradicals is reactivated by the plasma generated within the remote plasmasource. In some embodiments, the hydrogen radicals pass through anapplicator tube into the cleaning chamber. In some embodiments, thehydrogen radicals pass through the showerhead to remove polymericresidues on the wafer.

The foregoing outlines features of several embodiments or examples sothat those skilled in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodiments orexamples introduced herein. Those skilled in the art should also realizethat such equivalent constructions do not depart from the spirit andscope of the present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A method, comprising: providing an adjustabledistributor assembly disposed within a showerhead configured to provideselectively adjustable openings through which a cleaning materialpasses, wherein the adjustable distributor assembly comprises: a basesheet including base openings; and a plurality of control sheetsincluding control openings and configured to slidably mate with the basesheet to provide selectively adjustable openings; determining an initialvalue of a configurable parameter of an adjustable distributor assembly;performing an amount/thickness measurement of a layer includingpolymeric residues and metal oxide deposits at a cleaning surface of awafer by a monitoring device; determining whether a variation in theamount/thickness measurement is within an acceptable range; and inresponse to the variation in the amount/thickness measurement that isnot within the acceptable range, automatically adjusting theconfigurable parameter of the adjustable distributor assembly to set thevariation in the amount/thickness measurement within the acceptablerange so that the cleaning material that passes through the selectivelyadjustable openings of the adjustable distributor assembly reduces metaloxide deposits.
 2. The method of claim 1, wherein the configurableparameter includes one or more of an area of openings, a shape ofopenings, a region of openings, a type of gas, a flow rate or pressure,a gas/liquid temperature, and/or a showerhead height with respect to thecleaning surface of the wafer.
 3. The method of claim 2, furtherincluding: generating plasma within a remote plasma source that does notenter into a cleaning chamber.
 4. The method of claim 3, furtherincluding: reactivating hydrogen radicals by the plasma generated withinthe remote plasma source.
 5. The method of claim 4, further including:passing the hydrogen radicals through an applicator tube into thecleaning chamber.
 6. The method of claim 5, further including: passingthe hydrogen radicals through the showerhead to remove polymericresidues on the wafer.
 7. The method of claim 1, wherein the adjustabledistributor assembly further includes a plurality of control segmentspositioned between the base openings of the base sheet, wherein each ofthe plurality of control segments includes control openings that have adifferent diameter from each other.
 8. A method, comprising: determiningan initial value of a configurable parameter of an adjustabledistributor assembly; removing a layer at a cleaning surface of asubstrate by a cleaning material which passes through a showerhead;performing a measurement to determine if an amount of the layer removedis more than a threshold amount; and determining whether a variation inthe amount of the layer removed is within an acceptable range, whereinthe adjustable distributor assembly is disposed within the showerheadthrough which the cleaning material passes, the adjustable distributorassembly comprising: a base sheet including base openings; and aplurality of control sheets including control openings and configured toslidably mate with the base sheet to provide selectively adjustableopenings, wherein a plurality of control segments are positioned betweenthe base openings of the base sheet, and wherein each of the pluralityof control segments includes control openings that have a differentdiameter from each other.
 9. The method of claim 8, wherein theconfigurable parameter includes an overlapping amount of the baseopenings and the control openings that is adjustable from 0% to 100%,and an angular overlapping amount of the base openings and the controlopenings that is from 0 degree to 360 degrees.
 10. The method of claim8, wherein the performing a measurement to determine if an amount of thelayer removed is more than a threshold amount is performed by a monitordevice.
 11. The method of claim 10, further comprising: generating asignal when the variation in the amount of the layer is not within theacceptable range.
 12. The method of claim 8, further comprising: inresponse to the variation in the amount of the layer removed that is notwithin the acceptable range, adjusting the configurable parameter of theadjustable distributor assembly to set the variation in the amount ofthe layer removed is within the acceptable range.
 13. The method ofclaim 12, further comprising: activating the cleaning material by aremote plasma source.
 14. The method of claim 8, wherein the cleaningmaterial includes at least one of helium gas, H₂O, argon gas, andhydrogen gas.
 15. A method for cleaning a wafer, comprising: providingan activated cleaning material into a chamber through a showerhead ontoa cleaning surface of a wafer, wherein an adjustable distributorassembly is disposed within the showerhead to provide selectivelyadjustable openings through which the activated cleaning materialpasses, wherein the adjustable distributor assembly comprises: a basesheet including base openings; and a plurality of control sheetsincluding control openings and configured to slidably mate with the basesheet to provide selectively adjustable openings, wherein a plurality ofcontrol segments is positioned between the base openings of the basesheet, and wherein each of the plurality of control segments includescontrol openings that have a different diameter from each other.
 16. Themethod of claim 15, wherein the activated cleaning material is activatedby a remote plasma source.
 17. The method of claim 15, furthercomprising: adjusting a position of the plurality of control sheetsrelative to the base sheet to adjust an amount of the activated cleaningmaterial passing through the adjustable distributor assembly.
 18. Themethod of claim 17, further comprising: moving the plurality of controlsheets by a driving mechanism.
 19. The method of claim 15, furthercomprising: monitoring an amount of a layer including polymeric residuesand/or metal oxide deposits at the cleaning surface of the wafer. 20.The method of claim 19, further comprising: stopping providing theactivated cleaning material when the amount of the layer includingpolymeric residues and/or metal oxide deposits at the cleaning surfaceof the wafer is below a threshold amount.